1. Second Quarter Questions

2. Concept Test The cores of the terrestrial worlds are made mostly of metal because ______. a.the terrestrial worlds as a whole are made mostly of metal. b.the core contained lots of radioactive elements that decayed into metals. c.metals sunk to the centers a long time ago when the interiors were molten throughout. d.None of the above.

3. Concept Test Given this description of planetary interiors, we expect: a.Smaller planets should cool off faster than bigger ones. b.Larger planets should have thinner lithospheres than smaller planets. c.There should be fewer signs of geological activity on the surfaces of smaller planets compared to larger ones. d.All of the above. e.None of the above.

4. Concept Test Which of the following is NOT generally true of all the terrestrial world lithospheres? a.The thickness of the lithosphere depends on interior temperature, with cooler interiors leading to thicker lithospheres. b.The lithosphere is broken into a set of large plates that float upon the softer rock below. c.The lithosphere extends from somewhere in the mantle all the way to the surface. d.Rock in the lithosphere is stronger than rock beneath it. e.None of the above.

5. Concept Test Recent evidence suggests that Mars, like Earth, once had a stronger magnetic field. Assuming this is true, which of the following could explain why Mars lacks a global magnetic field like that of Earth? a.Because Mars's interior is cooler than Earth's, its liquid core layer may not be undergoing convection. b.Mars is too far from the Sun to have a global magnetic field. c.The Martian core is made of rock, while Earth's core is made of metal. d.Mars rotates much slower than the Earth. e.All of the above.

6. Concept Test The choices below describe four hypothetical planets. Which one would you expect to have the hottest interior? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.) a.Size: same as Mars. Distance from Sun: same as Earth. Rotation rate: once every 18 hours. b.Size: twice as big as Earth. Distance from Sun: same as Mercury. Rotation rate: once every 6 months. c.Size: same as Venus. Distance from Sun: same as Mars. Rotation rate: once every 25 hours. d.Size: same as the Moon. Distance from Sun: same as Mars. Rotation rate: once every 10 days.

7. Concept Test Based on all we know about the terrestrial worlds, what single factor appears to play the most important role in a terrestrial planet's geological destiny? a.Its composition. b.Its size. c.Its distance from the Sun. d.Whether or not it has liquid water. e.None of the above.

8. Concept Test Scientists hypothesize that evidence for past liquid water will be found at Gusev Crater because: a.Chemical analysis from space shows signs of minerals that (on Earth) tend to primarily form in the presence of water. b.From orbit gullies are seen along the rim of Gusev Crater indicating that water has flowed down into the crater bottom. c.Morphologically, from orbit it looks as if water erosion produced a channel that would have caused standing water within Gusev Crater. d.Rocks found on the floor of the crater show signs of chemical alteration by water. e.None of the above.

9. Concept Test The Spirit rover inside Gusev Crater found: a.The rocks on the crater floor were all basalt. Any sedimentary rocks, if present, must be buried underneath them. b.Evidence of sedimenatry rock. c.Lots of olivine and other water bearing chemicals. d.All of the above. e.None of the above.

10. Concept Test Bedrock is the “holy grail” for a geologist because: a.Bedrock is sedimentary rock which is only formed in the presence of water. b.It provides you with a history of the chemical and geological processes that occurred in that exact spot. c.Bedrock is not volcanic (basaltic) rock and thus tells you about the history of your location before the period of volcanic activity covered it up. d.All of the above. e.None of the above.

11. Concept Test Rock layers are important for geologists because: a.They record a history of formation. The lower down the layers the earlier in the planet’s history they were formed. b.Different layers mean different geological processes were at work on the surface and thus provided clues to past environments. c.Many geological processes, like erosion, create layers in rock and can be a strong sign of past water. d.All of the above. e.None of the above.

12. Concept Test The hypothesis that Meridiani Planum once had liquid water at or near its surface was supported by the observation of: a.Blueberries made of hematite and layered rock made of salts. b.Blueberries made of hematite and rocks with spindle –like depressions where water soluble crystals once resided. c.Blueberries made of hematite and rocks with wavy, cross- bedded layers that appear to have been formed by flowing water. d.Blueberries. e.All of the above.

13. Concept Test Endurance Crater was an important location to explore because: a.As a big hole in the ground, it offered easy access to its many layers. b.Its many layers showed a long history of chemical alteration by water. c.Its many layers offered a rich time-line of the geological processes that had been at work on Meridiani Planum. d.All of the above. e.None of the above.